Security system communicator and keypad device

Techniques are described for replacing a keypad of an existing security system within a property with a communication-enabled keypad device with dual functioning capabilities as a communicator device and a keypad device. In some implementations, data is received from a security panel of a property. A keypad bus protocol of the security panel is determined based on the data received from the security panel. Sensor data is received from one or more sensors located within the property. A monitoring system command that is not specified within a keypad bus of the security panel is determined based on based on the obtained sensor data. The monitoring system command is converted to a panel command using the keypad bus protocol. The panel command is transmitted on the keypad bus of the security panel.